This invention relates to fluid flow valves. More particularly, the invention relates to damper valves for controlling air flow in the ducts of ventilating systems.
Numerous kinds of control valves have been used in ventilating and other systems, and these include iris and butterfly valves. Most of these valves lack the advantage of simplicity of operation, and involve disadvantages such as high noise levels during operation in intermediate positions, and irregular control of the volume of air flow in relation to the control movement of the valve.